Fish Dinner, With a Side of Prozac

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Low-level residues of pharmaceuticals and personal care products (PPCPs) have been detected in fish collected by researchers from Baylor University and the Environmental Protection Agency—including the residue of one drug in wild fish that has not been previously reported.


The study “demonstrated for the first time that fish from several different locations across the country are exposed to multiple PPCPs in effluent-dominated waterways,” says Bryan Brooks, PhD, an associate professor of environmental sciences at Baylor in Waco, TX, and an aquatic toxicology expert.

Many aquatic systems throughout the United States routinely receive effluent discharges from wastewater treatment plants. Sometimes, the flow of streams and rivers can become dominated by these effluents.

While there are federal standards for treated wastewater, no guidelines or federal testing standards exist for pharmaceuticals or most personal care products in wastewater because their effects in surface waters are not well understood. The EPA undertook this pilot study as a part of an overall strategy to better understand the occurrence of PPCPs in surface waters, sediment and fish tissue.

Researchers collected fish from five effluent-dominated rivers in various parts of the country, including discharge areas of wastewater treatment plants in Chicago, Dallas, Orlando, Phoenix and West Chester, PA. They tested fish fillets and liver tissue for 24 different human medications, as well as 12 chemicals found in personal care products. Study results revealed:

  • The residue of seven pharmaceuticals and two personal care products was present in fish at all five effluent-dominated river sites. In many cases, multiple compounds were found in the same fish.
  • For the first time, gemfibrozil (Gemcor, Lopid), used to treat high cholesterol and triglyceride levels, was found in wild fish livers.
  • Drugs detected included diphenhydramine (Benadryl), an over-the-counter antihistamine that’s also found in nonprescription sleep aids and motion-sickness pills; diltiazem (Cardizem, Dilacor and other trade names), a drug for high blood pressure; carbamazepine (Tegretol, Epitol), a treatment for epilepsy and bipolar disorder; norfluoxetine, the active metabolite of the antidepressant fluoxetine (Prozac); and sertraline (Zoloft), an antidepressant.
  • Galaxolide and tonalide, fragrances used in soap and other personal care products, were found in fish fillet tissue from all five effluent-dominated river sites. Their concentrations in fish tissue were the highest of all compounds tested.

While the impact these compounds have on fish is not yet fully understood, the scientific literature has documented that antidepressant accumulation in fish may cause certain behavioral changes, which impact aggression, mating and other behaviors necessary for fish survival.

Based on these pilot study findings, the EPA is expanding its investigation of PPCPs in fish under its National Rivers and Streams Assessment. Fish collection began in 2008 and is continuing this year.

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